JP5941491B2 - Substrate processing apparatus, semiconductor device manufacturing method, and program - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a semiconductor device manufacturing method.

  In general, in a manufacturing process of a semiconductor device, a substrate processing apparatus that performs a process such as a film forming process on a substrate such as a wafer is used. As substrate processing apparatuses, single-wafer processing apparatuses that process substrates one by one are becoming widespread as the size of substrates increases and the accuracy of process processing increases.

  As a process performed by a single-wafer type substrate processing apparatus, for example, there is a film forming process by an alternate supply method. In the alternate supply process, the source gas supply process, the purge process, the reaction gas supply process, and the purge process are set as one cycle for the substrate in the processing space, and this cycle is repeated a predetermined number of times (n cycles) to the substrate. The film is formed. Therefore, in order to efficiently perform the alternate supply process, it is required to achieve both uniform gas supply to the substrate in the processing space and quick exhaust of the residual gas from the processing space. From this, as a single-wafer type substrate processing apparatus, a processing gas is supplied to the processing space from the upper side through a shower head as a gas dispersion mechanism, and is provided so as to surround a lateral outer periphery of the processing space, Some are configured to discharge gas from the center of the substrate toward the outer peripheral side of the substrate (that is, the side of the processing space) through an exhaust buffer chamber connected to the downstream side of the exhaust pipe.

  By the way, in such a substrate processing apparatus, it is necessary to periodically remove unnecessary films (such as reaction byproducts) attached to a shower head, a processing space, and the like. For this reason, some single-wafer-type substrate processing apparatuses supply cleaning gas into the processing space via a shower head to perform cleaning processing on the processing space or the like (see, for example, Patent Document 1). In addition, the cleaning gas is directly supplied into the exhaust pipe located downstream in the gas exhaust direction from the processing space, and the cleaning process for the inside of the exhaust pipe, which is a place where by-products etc. are easily attached and difficult to remove. There is something to do (see, for example, Patent Document 2).

JP 2005-109194 A Japanese Patent Laid-Open No. 2004-2111168

  However, with the above-described prior art, there is a risk that the exhaust buffer chamber cannot be sufficiently and satisfactorily cleaned.

  For example, when the alternate supply process is performed on the substrate, the source gas and the reactive gas are alternately supplied into the processing space as described above. At this time, any gas may remain in the exhaust buffer chamber and an unintended reaction may occur in the exhaust buffer chamber. When an unintended reaction occurs, an unnecessary film, a by-product, or the like adheres to the inner wall of the exhaust buffer chamber. In particular, in the exhaust buffer chamber, unlike in the processing space, the temperature conditions and pressure conditions for forming a high-quality film are not established, so there is a film with poor characteristics with variations in film density, film thickness, etc. Will be formed. Such a film is easily peeled off due to pressure fluctuation when switching the gas supply, etc., and may enter the processing space to adversely affect the characteristics of the film on the substrate or to reduce the yield.

  These deposits can be removed by supplying a cleaning gas through a shower head. However, since the active cleaning gas is deactivated in the processing space before reaching the exhaust buffer chamber, the cleaning process for the exhaust buffer chamber may be insufficient. Further, even if the cleaning gas is supplied directly into the exhaust pipe, it cannot be said that the cleaning process for the exhaust buffer chamber located upstream is sufficiently performed.

  In order to sufficiently perform the cleaning process for the exhaust buffer chamber, it is conceivable that the deposits are removed manually by an operator during the apparatus maintenance. However, in that case, it leads to a significant increase in downtime, resulting in a problem that the operating efficiency of the apparatus is lowered. That is, it cannot be said that the cleaning process for the exhaust buffer chamber can be performed satisfactorily.

  Accordingly, the present invention provides a substrate processing apparatus and a method for manufacturing a semiconductor device that can sufficiently and satisfactorily perform cleaning processing on the exhaust buffer chamber even when gas exhaust is performed using the exhaust buffer chamber. The purpose is to provide.

According to one aspect of the invention,
A processing space for processing a substrate placed on the substrate placement surface;
A gas supply system for supplying gas into the processing space from the side facing the substrate mounting surface;
An exhaust buffer chamber configured to include at least a communication hole communicating with the processing space at a side of the processing space, and a gas flow blocking wall extending in a direction to block a gas flow through the communication hole;
A gas exhaust system for exhausting the gas flowing into the exhaust buffer chamber;
A cleaning gas supply pipe for supplying a cleaning gas into the exhaust buffer chamber from a connection point provided between the communication hole and the gas flow blocking wall;
A substrate processing apparatus is provided.

According to yet another aspect of the invention,
A space provided to surround a lateral outer periphery of the processing space while supplying gas from the side facing the substrate mounting surface to the substrate mounted on the substrate mounting surface in the processing space A substrate processing step of processing the substrate in the processing space by exhausting gas from the processing space using an exhaust buffer chamber having:
An exhaust buffer chamber cleaning step of cleaning the exhaust buffer chamber by supplying a cleaning gas into the exhaust buffer chamber from a cleaning gas supply pipe communicating with the space constituting the exhaust buffer chamber;
A method for manufacturing a semiconductor device is provided.

  According to the present invention, even when gas is exhausted using the exhaust buffer chamber, the cleaning process for the exhaust buffer chamber can be performed sufficiently and satisfactorily.

It is a schematic block diagram of the single wafer type substrate processing apparatus concerning one embodiment of the present invention. It is a perspective view which shows typically a specific example of the whole shape of the exhaust buffer chamber in the substrate processing apparatus of FIG. It is a sectional side view which shows typically a specific example of the cross-sectional shape of the exhaust buffer chamber in the substrate processing apparatus of FIG. It is a top view which shows typically a specific example of the planar shape of the exhaust buffer chamber in the substrate processing apparatus of FIG. It is a flowchart which shows the substrate processing process and cleaning process which concern on one Embodiment of this invention. It is a flowchart which shows the detail of the film-forming process in FIG.

<One Embodiment of the Present Invention>
An embodiment of the present invention will be described below with reference to the drawings.

(1) Configuration of Substrate Processing Apparatus The substrate processing apparatus according to the present embodiment is configured as a single-wafer type substrate processing apparatus that processes a substrate to be processed one by one.
Examples of the substrate to be processed include a semiconductor wafer substrate (hereinafter simply referred to as “wafer”) on which a semiconductor device (semiconductor device) is fabricated.
Examples of processing performed on such a substrate include etching, ashing, and film formation processing. In this embodiment, the film formation processing is particularly performed. A typical example of the film forming process is an alternate supply process.

  Hereinafter, the configuration of the substrate processing apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a single-wafer type substrate processing apparatus according to the present embodiment.

(Processing container)
As shown in FIG. 1, the substrate processing apparatus 100 includes a processing container 202. The processing container 202 is configured as a flat sealed container having a circular cross section, for example. Moreover, the processing container 202 is comprised, for example with metal materials, such as aluminum (Al) and stainless steel (SUS). In the processing container 202, a processing space 201 for processing a wafer 200 such as a silicon wafer as a substrate and a transfer space 203 through which the wafer 200 passes when the wafer 200 is transferred to the processing space 201 are formed. The processing container 202 includes an upper container 202a and a lower container 202b. A partition plate 204 is provided between the upper container 202a and the lower container 202b.

  An exhaust buffer chamber 209 is provided in the vicinity of the outer peripheral edge inside the upper container 202a. Details of the exhaust buffer chamber 209 will be described later.

  A substrate loading / unloading port 206 adjacent to the gate valve 205 is provided on the side surface of the lower container 202b, and the wafer 200 moves between a transfer chamber (not shown) via the substrate loading / unloading port 206. A plurality of lift pins 207 are provided at the bottom of the lower container 202b. Furthermore, the lower container 202b is grounded.

(Substrate support part)
In the processing space 201, a substrate support unit 210 that supports the wafer 200 is provided. The substrate support unit 210 includes a substrate placement surface 211 on which the wafer 200 is placed, a substrate placement table 212 having the substrate placement surface 211 on the surface, a heater 213 as a heating source contained in the substrate placement table 212, It has mainly. The substrate mounting table 212 is provided with through holes 214 through which the lift pins 207 pass, respectively, at positions corresponding to the lift pins 207.

  The substrate mounting table 212 is supported by the shaft 217. The shaft 217 passes through the bottom of the processing container 202, and is further connected to the lifting mechanism 218 outside the processing container 202. By operating the elevating mechanism 218 to elevate and lower the shaft 217 and the substrate mounting table 212, the wafer 200 placed on the substrate placing surface 211 can be raised and lowered. In addition, the periphery of the lower end portion of the shaft 217 is covered with a bellows 219, and the inside of the processing container 202 is kept airtight.

When the wafer 200 is transferred, the substrate mounting table 212 is lowered to a position where the substrate mounting surface 211 faces the substrate loading / unloading port 206 (wafer transfer position). When the wafer 200 is processed, as shown in FIG. Ascent 200 moves up to a processing position (wafer processing position) in the processing space 201.
Specifically, when the substrate mounting table 212 is lowered to the wafer transfer position, the upper end portion of the lift pins 207 protrudes from the upper surface of the substrate mounting surface 211, and the lift pins 207 support the wafer 200 from below. Yes. When the substrate mounting table 212 is raised to the wafer processing position, the lift pins 207 are buried from the upper surface of the substrate mounting surface 211 so that the substrate mounting surface 211 supports the wafer 200 from below. In addition, since the lift pins 207 are in direct contact with the wafer 200, it is desirable to form the lift pins 207 from a material such as quartz or alumina.

(shower head)
A shower head 230 as a gas dispersion mechanism is provided in the upper portion of the processing space 201 (upstream side in the gas supply direction). The lid 231 of the shower head 230 is provided with a gas introduction hole 241, and a gas supply system (to be described later) is connected to the gas introduction hole 241. The gas introduced from the gas introduction hole 241 is supplied to the buffer space 232 of the shower head 230.

  The lid 231 of the shower head 230 is formed of a conductive metal and is used as an electrode for generating plasma in the buffer space 232 or the processing space 201. An insulating block 233 is provided between the lid 231 and the upper container 202a to insulate between the lid 231 and the upper container 202a.

  The shower head 230 includes a dispersion plate 234 for dispersing the gas supplied from the gas supply system via the gas introduction hole 241. The upstream side of the dispersion plate 234 is a buffer space 232, and the downstream side is a processing space 201. The dispersion plate 234 is provided with a plurality of through holes 234a. The dispersion plate 234 is disposed so as to face the substrate placement surface 211.

  The buffer space 232 is provided with a gas guide 235 that forms a flow of the supplied gas. The gas guide 235 has a conical shape whose diameter increases with the gas introduction hole 241 as a vertex toward the dispersion plate 234. The gas guide 235 is formed such that the lower end thereof is positioned further on the outer peripheral side than the through hole 234a formed on the outermost peripheral side of the dispersion plate 234.

(Plasma generator)
A matching unit 251 and a high frequency power source 252 are connected to the lid 231 of the shower head 230. Then, the plasma is generated in the shower head 230 and the processing space 201 by adjusting the impedance by the high-frequency power source 252 and the matching unit 251.

(Gas supply system)
A common gas supply pipe 242 is connected to the gas introduction hole 241 provided in the lid 231 of the shower head 230. The common gas supply pipe 242 communicates with the buffer space 232 in the shower head 230 by connection to the gas introduction hole 241. The common gas supply pipe 242 is connected to a first gas supply pipe 243a, a second gas supply pipe 244a, and a third gas supply pipe 245a. The second gas supply pipe 244a is connected to the common gas supply pipe 242 via a remote plasma unit (RPU) 244e.

  Among these, the source gas is mainly supplied from the source gas supply system 243 including the first gas supply pipe 243a, and the reaction gas is mainly supplied from the reaction gas supply system 244 including the second gas supply pipe 244a. . From the purge gas supply system 245 including the third gas supply pipe 245a, an inert gas is mainly supplied when the wafer 200 is processed, and a cleaning gas is mainly supplied when the shower head 230 and the processing space 201 are cleaned. Is done. Regarding the gas supplied from the gas supply system, the source gas is the first gas, the reactive gas is the second gas, the inert gas is the third gas, and the cleaning gas (for the processing space 201) is the fourth gas. Sometimes called gas. Furthermore, a cleaning gas (for the exhaust buffer chamber 209) supplied by an exhaust buffer chamber cleaning gas supply system, which will be described later, which is one of the gas supply systems, may be referred to as a fifth gas.

(Raw gas supply system)
The first gas supply pipe 243a is provided with a raw material gas supply source 243b, a mass flow controller (MFC) 243c which is a flow rate controller (flow rate control unit), and a valve 243d which is an on-off valve in order from the upstream direction. The source gas is supplied from the first gas supply pipe 243a into the shower head 230 via the MFC 243c, the valve 243d, and the common gas supply pipe 242.

The source gas is one of the processing gases, for example, SiCl ₆ (Disilicon hexachloride or Hexachlorodisilane) gas (ie, SiCl ₆ gas) which is a source containing Si (silicon) element. The source gas may be any of solid, liquid, and gas at normal temperature and pressure. When the source gas is liquid at normal temperature and pressure, a vaporizer (not shown) may be provided between the first gas supply source 243b and the mass flow controller 243c. Here, it will be described as gas.

  A source gas supply system 243 is mainly configured by the first gas supply pipe 243a, the MFC 243c, and the valve 243d. The source gas supply system 243 may be considered to include a source gas supply source 243b and a first inert gas supply system described later. The source gas supply system 243 supplies a source gas that is one of the processing gases, and thus corresponds to one of the processing gas supply systems.

  The downstream end of the first inert gas supply pipe 246a is connected to the downstream side of the valve 243d of the first gas supply pipe 243a. The first inert gas supply pipe 246a is provided with an inert gas supply source 246b, a mass flow controller (MFC) 246c, which is a flow rate controller (flow rate control unit), and a valve 246d, which is an on-off valve, in order from the upstream direction. ing. Then, the inert gas is supplied from the first inert gas supply pipe 246a into the shower head 230 via the MFC 246c, the valve 246d, and the first gas supply pipe 243a.

The inert gas acts as a carrier gas for the raw material gas, and it is preferable to use a gas that does not react with the raw material. Specifically, for example, nitrogen (N ₂ ) gas can be used. In addition to N ₂ gas, for example, a rare gas such as helium (He) gas, neon (Ne) gas, or argon (Ar) gas can be used.

  A first inert gas supply system is mainly configured by the first inert gas supply pipe 246a, the MFC 246c, and the valve 246d. Note that the first inert gas supply system may include the inert gas supply source 236b and the first gas supply pipe 243a. The first inert gas supply system may be included in the source gas supply system 243.

(Reactive gas supply system)
The second gas supply pipe 244a is provided with an RPU 244e downstream. In the upstream, a reactive gas supply source 244b, a mass flow controller (MFC) 244c, which is a flow rate controller (flow rate control unit), and a valve 244d, which is an on-off valve, are provided in this order from the upstream direction. Then, the reactive gas is supplied from the second gas supply pipe 244a into the shower head 230 via the MFC 244c, the valve 244d, the RPU 244e, and the common gas supply pipe 242. The reactive gas is brought into a plasma state by the remote plasma unit 244e and irradiated onto the wafer 200.

The reaction gas is one of the processing gases, and for example, ammonia (NH ₃ ) gas is used.

  A reactive gas supply system 244 is mainly configured by the second gas supply pipe 244a, the MFC 244c, and the valve 244d. Note that the reactive gas supply system 244 may include a reactive gas supply source 244b, an RPU 244e, and a second inert gas supply system described later. The reactive gas supply system 244 supplies a reactive gas that is one of the processing gases, and therefore corresponds to the other of the processing gas supply system.

  A downstream end of the second inert gas supply pipe 247a is connected to the downstream side of the valve 244d of the second gas supply pipe 244a. The second inert gas supply pipe 247a is provided with an inert gas supply source 247b, a mass flow controller (MFC) 247c, which is a flow rate controller (flow rate control unit), and a valve 247d, which is an on-off valve, in order from the upstream direction. ing. Then, the inert gas is supplied from the second inert gas supply pipe 247a into the shower head 230 via the MFC 247c, the valve 247d, the second gas supply pipe 244a, and the RPU 244e.

The inert gas acts as a carrier gas or diluent gas for the reaction gas. Specifically, for example, nitrogen (N ₂ ) gas can be used. In addition to N ₂ gas, for example, a rare gas such as helium (He) gas, neon (Ne) gas, or argon (Ar) gas may be used.

  A second inert gas supply system is mainly configured by the second inert gas supply pipe 247a, the MFC 247c, and the valve 247d. Note that the second inert gas supply system may include the inert gas supply source 247b, the second gas supply pipe 243a, and the RPU 244e. The second inert gas supply system may be included in the reaction gas supply system 244.

(Purge gas supply system)
The third gas supply pipe 245a is provided with a purge gas supply source 245b, a mass flow controller (MFC) 245c, which is a flow rate controller (flow rate control unit), and a valve 245d, which is an on-off valve, in order from the upstream direction. In the substrate processing step, an inert gas as a purge gas is supplied from the third gas supply pipe 245a into the shower head 230 through the MFC 245c, the valve 245d, and the common gas supply pipe 242. In the processing space cleaning process, an inert gas as a cleaning gas carrier gas or a dilution gas is supplied into the shower head 230 via the MFC 245c, the valve 245d, and the common gas supply pipe 242 as necessary. .

The inert gas supplied from the purge gas supply source 245b acts as a purge gas for purging the gas remaining in the processing container 202 and the shower head 230 in the substrate processing step. In the process space cleaning step, it may act as a carrier gas or a dilution gas for the cleaning gas. Specifically, for example, nitrogen (N ₂ ) gas can be used as the inert gas. In addition to N ₂ gas, for example, a rare gas such as helium (He) gas, neon (Ne) gas, or argon (Ar) gas may be used.

  A purge gas supply system 245 is mainly configured by the third gas supply pipe 245a, the MFC 245c, and the valve 245d. The purge gas supply system 245 may be considered to include a purge gas supply source 245b and a processing space cleaning gas supply system described later.

(Processing space cleaning gas supply system)
A downstream end of the processing space cleaning gas supply pipe 248a is connected to the downstream side of the valve 245d of the third gas supply pipe 245a. The processing space cleaning gas supply pipe 248a is provided with a processing space cleaning gas supply source 248b, a mass flow controller (MFC) 248c that is a flow rate controller (flow rate control unit), and a valve 248d that is an on-off valve in order from the upstream direction. ing. In the process space cleaning step, the third gas supply pipe 245a is supplied with cleaning gas into the shower head 230 via the MFC 248c, the valve 248d, and the common gas supply pipe 242.

The cleaning gas supplied from the processing space cleaning gas supply source 248b acts as a cleaning gas for removing by-products and the like attached to the shower head 230 and the processing container 202 in the processing space cleaning process. Specifically, for example, nitrogen trifluoride (NF ₃ ) gas may be used as the cleaning gas. Further, for example, hydrogen fluoride (HF) gas, chlorine trifluoride gas (ClF ₃ ) gas, fluorine (F ₂ ) gas, or the like may be used, or a combination thereof may be used.

  A processing space cleaning gas supply system is mainly configured by the processing space cleaning gas supply pipe 248a, the MFC 248c, and the valve 248d. The processing space cleaning gas supply system may include the processing space cleaning gas supply source 248b and the third gas supply pipe 245a. Further, the processing space cleaning gas supply system may be included in the purge gas supply system 245.

(Exhaust buffer chamber cleaning gas supply system)
The substrate processing apparatus 100 includes an exhaust buffer chamber cleaning gas supply system 249 as a gas supply system in addition to the processing space cleaning gas supply system. The exhaust buffer chamber cleaning gas supply system 249 includes an exhaust buffer chamber cleaning gas supply pipe (hereinafter simply referred to as “cleaning gas supply pipe”) 249 a that directly communicates with the upper surface side of the exhaust buffer chamber 209. The cleaning gas supply pipe 249a is provided with an exhaust buffer chamber cleaning gas supply source 249b, a mass flow controller (MFC) 249c, which is a flow rate controller (flow rate control unit), and a valve 249d, which is an on-off valve, in order from the upstream direction. Yes. The cleaning gas is supplied from the cleaning gas supply pipe 249a into the exhaust buffer chamber 209 via the MFC 249c and the valve 249d.

The cleaning gas supplied from the exhaust buffer chamber cleaning gas supply source 249 b acts as a cleaning gas for removing by-products and the like attached to the inner wall of the exhaust buffer chamber 209. Specifically, for example, nitrogen trifluoride (NF ₃ ) gas may be used as the cleaning gas. Further, for example, hydrogen fluoride (HF) gas, chlorine trifluoride (ClF ₃ ) gas, fluorine (F ₂ ) gas, or the like may be used, or a combination thereof may be used. The exhaust buffer chamber cleaning gas supply source 249b is not necessarily provided separately from the processing space cleaning gas supply source 248b when supplying the same type of cleaning gas as the processing space cleaning gas supply source 248b. You may make it share.

  An exhaust buffer chamber cleaning gas supply system 249 is mainly configured by the cleaning gas supply pipe 249a, the MFC 249c, and the valve 249d. The exhaust buffer chamber cleaning gas supply system 249 may include the exhaust buffer chamber cleaning gas supply source 249b.

(Gas exhaust system)
An exhaust system that exhausts the atmosphere of the processing container 202 includes a plurality of exhaust pipes connected to the processing container 202. Specifically, a first exhaust pipe (not shown) connected to the transfer space 203 of the lower container 202b, a second exhaust pipe 222 connected to the exhaust buffer chamber 209 of the upper container 202a, and the shower head 230 A third exhaust pipe 236 connected to the buffer space 232.

(First gas exhaust system)
The first exhaust pipe is connected to the side surface or the bottom surface of the transfer space 203. The first exhaust pipe is provided with a turbo molecular pump (TMP) (not shown) as a vacuum pump that realizes a high vacuum or an ultra-high vacuum. In the first exhaust pipe, a valve (not shown) is provided on the downstream side or the upstream side of the TMP, or both. The first exhaust pipe may be provided with a dry pump (DP) (not shown) in addition to TMP. DP functions as its auxiliary pump when TMP operates. That is, TMP and DP exhaust the atmosphere of the conveyance space 203 through the first exhaust pipe. At that time, it is difficult for TMP, which is a high vacuum (or ultra-high vacuum) pump, to evacuate to atmospheric pressure alone, and therefore DP is used as an auxiliary pump that evacuates to atmospheric pressure.

  A first gas exhaust system is mainly configured by the first exhaust pipe, TMP, DP, and valves.

(Second gas exhaust system)
The second exhaust pipe 222 is connected to the exhaust buffer chamber 209 via an exhaust hole 221 provided on the upper surface or side of the exhaust buffer chamber 209. The second exhaust pipe 222 is provided with an APC (Auto Pressure Controller) 223 which is a pressure controller for controlling the inside of the processing space 201 communicating with the exhaust buffer chamber 209 to a predetermined pressure. The APC 223 has a valve element (not shown) whose opening degree can be adjusted, and adjusts the conductance of the second exhaust pipe 222 in accordance with an instruction from the controller 260 described later. In the second exhaust pipe 222, a vacuum pump 224 is provided on the downstream side of the APC 223. The vacuum pump 224 exhausts the atmosphere of the exhaust buffer chamber 209 and the processing space 201 communicating with the exhaust buffer chamber 209 through the second exhaust pipe 222. In the second exhaust pipe 222, a valve (not shown) is provided on the downstream side or the upstream side of the APC 223, or both.

  A second gas exhaust system is mainly configured by the second exhaust pipe 222, the APC 223, the vacuum pump 224, and a valve (not shown). The vacuum pump 224 may share the DP in the first gas exhaust system.

(Third gas exhaust system)
The third exhaust pipe 236 is connected to the upper surface or side surface of the buffer space 232. That is, the third exhaust pipe 236 is connected to the shower head 230 and thereby communicates with the buffer space 232 in the shower head 230. A valve 237 is provided in the third exhaust pipe 236. In the third exhaust pipe 236, a pressure regulator 238 is provided on the downstream side of the valve 237. Further, a vacuum pump 239 is provided in the third exhaust pipe 236 on the downstream side of the pressure regulator 238. The vacuum pump 239 exhausts the atmosphere of the buffer space 232 through the third exhaust pipe 236.

  A third gas exhaust system is mainly configured by the third exhaust pipe 236, the valve 237, the pressure regulator 238, and the vacuum pump 239. Note that the vacuum pump 239 may share the DP in the first gas exhaust system.

(controller)
The substrate processing apparatus 100 includes a controller 260 that controls the operation of each unit of the substrate processing apparatus 100. The controller 260 includes at least a calculation unit 261 and a storage unit 262. The controller 260 is connected to each configuration described above, calls a program or recipe from the storage unit 262 in accordance with an instruction from the host controller or the user, and controls the operation of each configuration in accordance with the contents. Specifically, the controller 260 includes a gate valve 205, a lifting mechanism 218, a heater 213, a high frequency power supply 252, a matching unit 251, MFCs 243c to 248c, valves 243d to 248d, MFC 249c, valves 249d, APC 223, TMP, DP, vacuum pump The operation of 224, 239, valve 237, etc. is controlled.

  The controller 260 may be configured as a dedicated computer or a general-purpose computer. For example, an external storage device storing the above-described program (for example, magnetic tape, magnetic disk such as a flexible disk or hard disk, optical disk such as CD or DVD, magneto-optical disk such as MO, semiconductor memory such as USB memory or memory card) And installing the program in a general-purpose computer using the external storage device, the controller 260 according to this embodiment can be configured.

  The means for supplying the program to the computer is not limited to supplying the program via an external storage device. For example, the program may be supplied without using an external storage device by using communication means such as the Internet or a dedicated line. Note that the storage unit 262 and the external storage device are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as a recording medium. Note that when the term “recording medium” is used in this specification, it may include only the storage unit 262 alone, only the external storage device alone, or both.

(2) Details of Exhaust Buffer Chamber Here, the exhaust buffer chamber 209 formed in the upper container 202a of the processing container 202 will be described in detail with reference to FIGS.

  FIG. 2 is a perspective view schematically showing a specific example of the overall shape of the exhaust buffer chamber according to the present embodiment. FIG. 3 is a side sectional view schematically showing a specific example of the sectional shape of the exhaust buffer chamber according to the present embodiment. FIG. 4 is a plan view schematically showing a specific example of the planar shape of the exhaust buffer chamber according to the present embodiment.

(Overall shape)
The exhaust buffer chamber 209 functions as a buffer space when the gas in the processing space 201 is discharged toward the side periphery. For this purpose, the exhaust buffer chamber 209 has a space provided so as to surround the outer periphery of the processing space 201 as shown in FIG. That is, the exhaust buffer chamber 209 has a space formed in a ring shape (annular shape) in plan view on the outer peripheral side of the processing space 201.

(Cross-sectional shape)
As shown in FIG. 3, in the space of the exhaust buffer chamber 209, a ceiling surface and both side wall surfaces of the space are formed by the upper container 202 a, and a floor surface of the space is formed by the partition plate 204. A communication hole 209b communicating with the processing space 201 is provided on the inner peripheral side of the space, and the gas supplied into the processing space 201 through the communication hole 209b flows into the space. . The gas flowing into the space is blocked by the outer peripheral side wall surface 209a constituting the space and collides with the side wall surface 209a. That is, one side wall (outer peripheral side wall) constituting the space functions as a gas flow blocking wall 209a extending in a direction blocking the flow of gas passing through the communication hole 209b. In addition, a communication hole 209 b communicating with the processing space 201 is provided on the other side wall (inner peripheral side wall) facing the gas flow blocking wall 209 a. Thus, the exhaust buffer chamber 209 includes at least a communication hole 209b that communicates with the processing space 201 on the side of the processing space 201, and a gas flow blocking wall 209a that extends in a direction that blocks the flow of gas through the communication hole 209b. , And is configured.

  Note that the space of the exhaust buffer chamber 209 is configured to extend so as to surround the outer periphery of the processing space 201. Therefore, the communication hole 209b provided in the inner peripheral side wall of the space is also provided so as to extend over the entire outer periphery of the side of the processing space 201. At this time, considering that the exhaust buffer chamber 209 functions as a buffer space for gas exhaust, the size of the communication hole 209b in the side sectional height direction is the size of the space of the exhaust buffer chamber 209 in the side sectional height direction. It is preferable that the height is smaller than the height (space height).

(Exhaust system connection)
As shown in FIG. 2, the second exhaust pipe 222 of the second gas exhaust system is connected to the space of the exhaust buffer chamber 209. As a result, the gas supplied into the processing space 201 flows into the exhaust buffer chamber 209 through the communication hole 209b serving as a gas flow path between the processing space 201 and the exhaust buffer chamber 209 (see the arrow in the figure). The inflowing gas is exhausted through the second exhaust pipe 222. With such a structure, the gas in the processing space 201 can be quickly exhausted. Further, the air can be uniformly exhausted from the wafer in the outer peripheral direction. Therefore, gas can be uniformly supplied to the wafer surface, and as a result, the substrate surface can be processed uniformly.

(Cleaning gas supply system connection)
Further, as shown in FIG. 2, a cleaning gas supply pipe 249a of the exhaust buffer chamber cleaning gas supply system 249 is connected to the upper surface side of the space of the exhaust buffer chamber 209. As a result, the cleaning gas supplied from the exhaust buffer chamber cleaning gas supply source 249b is supplied to the exhaust buffer chamber 209 through the cleaning gas supply pipe 249a.

  As shown in FIG. 3, the cleaning gas supply pipe 249 a connected to the exhaust buffer chamber 209 has a communication hole 209 b serving as a gas flow path from the processing space 201 to the exhaust buffer chamber 209, as shown in FIG. A connecting portion for the space is provided between the gas flow blocking wall 209a which is an outer peripheral side wall in the space constituting the exhaust buffer chamber 209. In other words, the cleaning gas supply pipe 249a supplies the cleaning gas into the exhaust buffer chamber 209 on the downstream side in the gas flow direction from the communication hole 209b and on the upstream side in the gas flow direction from the gas flow blocking wall 209a. I do.

  The cleaning gas supply pipe 249a is preferably connected to the exhaust buffer chamber 209 via the gas supply groove 249e in order to make the supply of the cleaning gas uniform into the exhaust buffer chamber 209.

  As shown in FIG. 2 or 3, the gas supply groove 249 e is formed on the ceiling surface of the space of the exhaust buffer chamber 209. Further, as shown in FIG. 4, the gas supply groove 249 e is formed to be continuous in the circumferential direction surrounding the processing space 201. That is, the gas supply groove 249e is formed so as to extend over the entire circumference of the exhaust buffer chamber 209. The groove cross-sectional shape constituting the gas supply groove 249e is not particularly limited as long as it is continuous in the circumferential direction, and may be a square groove shape as shown in the figure, or other shapes ( For example, it may be a round groove).

  If connected through such a gas supply groove 249e, even if only one cleaning gas supply pipe 249a is connected to the exhaust buffer chamber 209, the cleaning gas from the cleaning gas supply pipe 249a is gas. After reaching the entire circumference through the supply groove 249e, the gas is supplied into the exhaust buffer chamber 209. Accordingly, the supply of the cleaning gas to the exhaust buffer chamber 209 can be made uniform, and the supply of the cleaning gas to a specific location (for example, the vicinity of the connection location of the cleaning gas supply pipe 249a) is suppressed. be able to.

  However, the cleaning gas supply pipe 249a is not necessarily connected to the exhaust buffer chamber 209 via the gas supply groove 249e as long as the supply of the cleaning gas can be made uniform. For example, if a plurality of cleaning gas supply pipes 249a can be installed, it may be configured that each cleaning gas supply pipe 249a and the exhaust buffer chamber 209 are connected at a plurality of locations. The supply of the cleaning gas to the inside of the 209 can be made uniform.

(3) Substrate Processing Step Next, a step of forming a thin film on the wafer 200 using the substrate processing apparatus 100 as one step of the semiconductor device manufacturing method will be described. In the following description, the operation of each unit constituting the substrate processing apparatus 100 is controlled by the controller 260.

Here, a SiCl ₆ gas is used as a source gas (first processing gas), an NH ₃ gas is used as a reaction gas (second processing gas), and a SiN (silicon nitride) film is formed as a silicon-containing film on the wafer 200. An example in which is formed by an alternate supply method will be described.

  FIG. 5 is a flowchart showing a substrate processing process and a cleaning process according to this embodiment. FIG. 6 is a flowchart showing details of the film forming process of FIG.

(Substrate loading / mounting process: S102)
In the substrate processing apparatus 100, first, the substrate mounting table 212 is lowered to the transfer position of the wafer 200, thereby causing the lift pins 207 to pass through the through holes 214 of the substrate mounting table 212. As a result, the lift pins 207 protrude from the surface of the substrate mounting table 212 by a predetermined height. Subsequently, the gate valve 205 is opened to allow the transfer space 203 to communicate with the transfer chamber (not shown). Then, the wafer 200 is loaded into the transfer space 203 from the transfer chamber using a wafer transfer machine (not shown), and the wafer 200 is transferred onto the lift pins 207. Thereby, the wafer 200 is supported in a horizontal posture on the lift pins 207 protruding from the surface of the substrate mounting table 212.

  When the wafer 200 is loaded into the processing container 202, the wafer transfer machine is retracted out of the processing container 202, the gate valve 205 is closed, and the inside of the processing container 202 is sealed. Thereafter, by raising the substrate mounting table 212, the wafer 200 is mounted on the substrate mounting surface 211 provided on the substrate mounting table 212, and by further raising the substrate mounting table 212, the processing space 201 described above. The wafer 200 is raised to the processing position inside.

When the wafer 200 is carried into the processing container 202, the valve in the first gas exhaust system is opened (opened) to allow communication between the transfer space 203 and TMP, and between TMP and DP. To communicate. On the other hand, the valves of the exhaust system other than the valve in the first gas exhaust system are closed (closed). Thereby, the atmosphere of the transfer space 203 is exhausted by TMP and DP, and the processing container 202 is brought into a high vacuum (ultra-high vacuum) state (for example, 10 ⁻⁵ Pa or less). In this process, the processing vessel 202 is brought into a high vacuum (ultra-high vacuum) state in the same manner as the pressure difference from the transfer chamber maintained in a high vacuum (ultra-high vacuum) state (for example, 10 ⁻⁶ Pa or less). This is to reduce the above. In this state, the gate valve 205 is opened, and the wafer 200 is loaded into the transfer space 203 from the transfer chamber. Note that TMP and DP are always operating during the steps shown in FIGS. 5 and 6 so as not to cause a delay in the processing steps accompanying the rise of their operations.

  After the wafer 200 is carried into the transfer space 203 and then moved up to the processing position in the processing space 201, the valve in the first gas exhaust system is closed. Thereby, the space between the transfer space 203 and the TMP is cut off, and the exhaust of the transfer space 203 by the TMP ends. On the other hand, the valve in the second gas exhaust system is opened to allow communication between the exhaust buffer chamber 209 and the APC 223 and communication between the APC 223 and the vacuum pump 224. The APC 223 controls the exhaust flow rate of the exhaust buffer chamber 209 by the vacuum pump 224 by adjusting the conductance of the second exhaust pipe 222 and maintains the processing space 201 communicating with the exhaust buffer chamber 209 at a predetermined pressure. The other exhaust system valves remain closed. Also, when closing the valve in the first gas exhaust system, the valve located on the upstream side of the TMP is closed, and then the valve located on the downstream side of the TMP is closed to stabilize the operation of the TMP. To maintain.

In this step, N ₂ gas as an inert gas may be supplied into the processing container 202 from the inert gas supply system while the processing container 202 is exhausted. That is, the N ₂ gas may be supplied into the processing container 202 by opening at least the valve 245d of the third gas supply system while exhausting the processing container 202 through the exhaust buffer chamber 209 with TMP or DP. . As a result, it is possible to suppress the adhesion of particles on the wafer 200.

  Further, when the wafer 200 is placed on the substrate mounting table 212, power is supplied to the heater 213 embedded in the substrate mounting table 212 so that the surface of the wafer 200 is controlled to a predetermined processing temperature. The At this time, the temperature of the heater 213 is adjusted by controlling the power supply to the heater 213 based on temperature information detected by a temperature sensor (not shown).

  In this manner, in the substrate carrying-in / placement process (S102), the inside of the processing space 201 is controlled to be a predetermined processing pressure, and the surface temperature of the wafer 200 is controlled to be a predetermined processing temperature. Here, the predetermined processing temperature and processing pressure are processing temperature and processing pressure at which a SiN film can be formed by an alternate supply method in a film forming step (S104) described later. That is, the processing temperature and the processing pressure are such that the source gas supplied in the first processing gas (source gas) supply step (S202) does not self-decompose. Specifically, it is conceivable that the treatment temperature is from room temperature to 500 ° C., preferably from room temperature to 400 ° C., and the treatment pressure is from 50 to 5000 Pa. This processing temperature and processing pressure are also maintained in the film forming step (S104) described later.

(Film formation process: S104)
After the substrate carry-in / placement step (S102), the film formation step (S104) is performed next. Hereinafter, the film forming step (S104) will be described in detail with reference to FIG. The film forming step (S104) is a cyclic process that repeats a process of alternately supplying different process gases.

(First process gas supply step: S202)
In the film formation step (S104), first, a first process gas (raw material gas) supply step (S202) is performed. When the first processing gas is a liquid source such as TiCl ₄ , the source gas is vaporized to generate (preliminarily vaporize) the source gas (ie, TiCl ₄ gas). The preliminary vaporization of the source gas may be performed in parallel with the above-described substrate carry-in / placement step (S102). This is because a predetermined time is required to stably generate the source gas.

When supplying the first processing gas, the source gas (SiCl ₆ gas) into the processing space 201 is adjusted by opening the valve 243d and adjusting the mass flow controller 243c so that the flow rate of the raw material gas becomes a predetermined flow rate. Start supplying. The supply flow rate of the source gas is, for example, 100 to 500 sccm. The source gas is dispersed by the shower head 230 and is uniformly supplied onto the wafer 200 in the processing space 201.

At this time, the valve 246d of the first inert gas supply system is opened, and the inert gas (N ₂ gas) is supplied from the first inert gas supply pipe 246a. The supply flow rate of the inert gas is, for example, 500 to 5000 sccm. Note that an inert gas may flow from the third gas supply pipe 245a of the purge gas supply system.

  Excess source gas uniformly flows from the processing space 201 into the exhaust buffer chamber 209 and flows through the second exhaust pipe 222 of the second gas exhaust system to be exhausted. Specifically, a valve in the second gas exhaust system is opened, and the APC 223 is controlled so that the pressure in the processing space 201 becomes a predetermined pressure. All the valves of the exhaust system other than the valves in the second gas exhaust system are closed.

  At this time, the processing temperature and the processing pressure in the processing space 201 are set to a processing temperature and a processing pressure at which the source gas is not self-decomposed. Therefore, gas molecules of the source gas are adsorbed on the wafer 200.

  After a predetermined time has elapsed after starting the supply of the source gas, the valve 243d is closed and the supply of the source gas is stopped. The supply time of the source gas and the carrier gas is, for example, 2 to 20 seconds.

(First shower head exhaust process: S204)
After the supply of the source gas is stopped, an inert gas (N ₂ gas) is supplied from the third gas supply pipe 245a, and the shower head 230 is purged. At this time, the valve of the second gas exhaust system is closed while the valve 237 of the third gas exhaust system is opened. The other gas exhaust system valves remain closed. That is, when purging the shower head 230, the space between the exhaust buffer chamber 209 and the APC 223 is shut off, the pressure control by the APC 223 is stopped, and the buffer space 232 and the vacuum pump 239 are communicated. Thereby, the source gas remaining in the shower head 230 (buffer space 232) is exhausted from the shower head 230 by the vacuum pump 239 via the third exhaust pipe 236. At this time, the valve on the downstream side of the APC 223 may be opened.

The supply flow rate of the inert gas (N ₂ gas) in the first shower head exhausting step (S204) is, for example, 1000 to 10000 sccm. The supply time of the inert gas is, for example, 2 to 10 seconds.

(First processing space exhaust process: S206)
When the purge of the shower head 230 is completed, an inert gas (N ₂ gas) is then supplied from the third gas supply pipe 245a, and the processing space 201 is purged. At this time, the valve in the second gas exhaust system is opened and controlled by the APC 223 so that the pressure in the processing space 201 becomes a predetermined pressure. On the other hand, all the valves of the gas exhaust system other than the valves in the second gas exhaust system are closed. Thereby, the raw material gas that could not be adsorbed to the wafer 200 in the first process gas supply step (S202) is processed through the second exhaust pipe 222 and the exhaust buffer chamber 209 by the vacuum pump 224 in the second gas exhaust system. It is removed from the space 201.

The supply flow rate of the inert gas (N ₂ gas) in the first processing space exhaust process (S206) is, for example, 1000 to 10000 sccm. The supply time of the inert gas is, for example, 2 to 10 seconds.

  Here, the first processing space exhausting step (S206) is performed after the first showerhead exhausting step (S204), but the order of performing these steps may be reversed. Also, these steps may be performed simultaneously.

(Second process gas supply step: S208)
When the purging of the shower head 230 and the processing space 201 is completed, a second processing gas (reactive gas) supply step (S208) is subsequently performed. In the second process gas supply step (S208), the valve 244d is opened, and the supply of the reaction gas (NH ₃ gas) into the process space 201 is started via the remote plasma unit 244e and the shower head 230. At this time, the MFC 244c is adjusted so that the flow rate of the reaction gas becomes a predetermined flow rate. The supply flow rate of the reaction gas is, for example, 1000 to 10000 sccm.

  The plasma reaction gas is dispersed by the shower head 230 and is uniformly supplied onto the wafer 200 in the processing space 201, reacts with the source gas-containing film adsorbed on the wafer 200, and forms SiN on the wafer 200. Create a film.

At this time, the valve 247d of the second inert gas supply system is opened, and an inert gas (N ₂ gas) is supplied from the second inert gas supply pipe 247a. The supply flow rate of the inert gas is, for example, 500 to 5000 sccm. Note that an inert gas may flow from the third gas supply pipe 245a of the purge gas supply system.

  Excess reaction gas and reaction by-products flow into the exhaust buffer chamber 209 from the processing space 201 and flow through the second exhaust pipe 222 of the second gas exhaust system to be exhausted. Specifically, a valve in the second gas exhaust system is opened, and the APC 223 is controlled so that the pressure in the processing space 201 becomes a predetermined pressure. All the valves of the exhaust system other than the valves in the second gas exhaust system are closed.

  After a predetermined time has elapsed since the start of the supply of the reaction gas, the valve 244d is closed and the supply of the reaction gas is stopped. The supply time of the reaction gas and the carrier gas is, for example, 2 to 20 seconds.

(Second shower head exhaust process: S210)
After stopping the supply of the reaction gas, the second shower head exhausting step (S210) is performed to remove the reaction gas and reaction byproducts remaining in the shower head 230. Since the second shower head exhausting step (S210) may be performed in the same manner as the first shower head exhausting step (S204) already described, description thereof is omitted here.

(Second processing space exhaust process: S212)
After the purging of the shower head 230 is completed, a second processing space exhausting step (S212) is then performed to remove the reaction gas and reaction byproducts remaining in the processing space 201. Since the second process space exhausting step (S212) may be performed in the same manner as the first process space exhausting step (S206) already described, the description thereof is omitted here.

(Determination step: S214)
The first process gas supply process (S202), the first shower head exhaust process (S204), the first process space exhaust process (S206), the second process gas supply process (S208), and the second shower. The head exhaust process (S210) and the second process space exhaust process (S212) are defined as one cycle, and the controller 260 determines whether or not this cycle has been performed a predetermined number of times (n cycles) (S214). When the cycle is performed a predetermined number of times, a silicon nitride (SiN) film having a desired thickness is formed on the wafer 200.

(Processing number determination step: S106)
After the film formation step (S104) including the above steps (S202 to S214), as shown in FIG. 5, next, has the wafer 200 processed in the film formation step (S104) reached a predetermined number? It is determined whether or not (S106).

  If the predetermined number of wafers 200 processed in the film forming step (S104) has not been reached, the processed wafers 200 are subsequently taken out and processing of new wafers 200 that are waiting next is started. Then, the process proceeds to the substrate carry-in / out step (S108). Further, when the film forming step (S104) is performed on a predetermined number of wafers 200, the processed wafer 200 is taken out and the wafer 200 is not present in the processing container 202. The process proceeds to step (S110).

(Substrate carry-in / out process: S108)
In the substrate carry-in / out step (S <b> 108), the substrate mounting table 212 is lowered, and the wafer 200 is supported on the lift pins 207 that protrude from the surface of the substrate mounting table 212. As a result, the wafer 200 changes from the processing position to the transfer position. Thereafter, the gate valve 205 is opened, and the wafer 200 is carried out of the processing container 202 using a wafer transfer machine. At this time, the valve 245d is closed, and supply of the inert gas from the third gas supply system into the processing container 202 is stopped.

In the substrate carry-in / out step (S108), while the wafer 200 moves from the processing position to the transfer position, the valve in the second gas exhaust system is closed and the pressure control by the APC 223 is stopped. On the other hand, by opening the valve in the first gas exhaust system and exhausting the atmosphere of the transfer space 203 by TMP and DP, the processing vessel 202 is brought into a high vacuum (ultra high vacuum) state (for example, 10 ⁻⁵ Pa or less). The pressure difference from the transfer chamber maintained in a high vacuum (ultra-high vacuum) state (for example, 10 ⁻⁶ Pa or less) is also reduced. In this state, the gate valve 205 is opened, and the wafer 200 is unloaded from the processing container 202 to the transfer chamber.

  Thereafter, in the substrate loading / unloading step (S108), a new wafer 200 waiting next is loaded into the processing container 202 in the same procedure as in the above-described substrate loading / mounting step (S102). The wafer 200 is raised to the processing position in the processing space 201, and the processing space 201 is set to a predetermined processing temperature and processing pressure so that the next film forming step (S104) can be started. Then, a film forming process (S104) and a process number determination process (S106) are performed on a new wafer 200 in the processing space 201.

(Substrate unloading step: S110)
In the substrate carry-out step (S110), the processed wafer 200 is taken out from the processing container 202 and carried out to the transfer chamber in the same procedure as in the substrate carry-in / out step (S108) described above. However, unlike the substrate carry-in / out step (S108), in the substrate carry-out step (S110), the new wafer 200 waiting next is not carried into the process vessel 202, and the inside of the process vessel 202 is not carried out. In this state, the wafer 200 is not present.

  When the substrate unloading process (S110) is completed, the process proceeds to the cleaning process.

(4) Cleaning Process Next, a process of cleaning the inside of the processing container 202 of the substrate processing apparatus 100 as one process of the semiconductor device manufacturing method will be described with reference to FIG.

(Exhaust buffer chamber cleaning process: S112)
In the substrate processing apparatus 100, every time the substrate unloading process (S110) is completed, that is, the film forming process (S104) is performed on a predetermined number of wafers 200, and then the wafer 200 does not exist in the processing container 202. Each time, an exhaust buffer chamber cleaning process (S112) is performed.

  When the film forming step (S104) is performed on the wafer 200, the exhaust gas from the processing space 201 flows into the exhaust buffer chamber 209 through the communication hole 209b and collides with the gas flow blocking wall 209a to block the flow. Thereafter, the gas stays temporarily in the exhaust buffer chamber 209 until exhausted from the second exhaust pipe 222 of the second gas exhaust system. For this purpose, when the film forming step (S104) is repeatedly performed on a predetermined number of wafers 200, the reaction by-products and the residual gases react particularly in the gas flow blocking wall 209a and in the vicinity thereof in the exhaust buffer chamber 209. Things are easy to deposit. For this reason, the substrate processing apparatus 100 performs the exhaust buffer chamber cleaning step (S112) each time the film forming step (S104) is performed on a predetermined number of wafers 200, thereby cleaning the exhaust buffer chamber 209. Do it.

  In the exhaust buffer chamber cleaning step (S112), the valve 249d of the exhaust buffer chamber cleaning gas supply system 249 is opened, and the cleaning gas from the exhaust buffer chamber cleaning gas supply source 249b is fed into the exhaust buffer chamber 209 through the cleaning gas supply pipe 249a. Supply. The supplied cleaning gas removes deposits (such as reaction byproducts) adhering to the inner wall of the exhaust buffer chamber 209. The cleaning process performed by supplying the cleaning gas into the exhaust buffer chamber 209 from the cleaning gas supply pipe 249a is hereinafter referred to as “first cleaning process”.

  At this time, the cleaning gas supply pipe 249a is connected to the exhaust buffer chamber 209 between the communication hole 209b and the gas flow blocking wall 209a. Therefore, the cleaning gas is supplied into the exhaust buffer chamber 209 slightly upstream of the gas flow blocking wall 209a in the gas flow direction. Therefore, the cleaning gas is supplied in the vicinity of the gas flow blocking wall 209a, and the cleaning gas can reach the gas flow blocking wall 209a before being deactivated. Can be effectively removed.

  Furthermore, if the cleaning gas supply pipe 249a is connected to the exhaust buffer chamber 209 via the gas supply groove 249e, the cleaning gas travels all around the gas supply groove 249e and then enters the exhaust buffer chamber 209. Supplied. For this reason, the cleaning gas can be supplied uniformly into the exhaust buffer chamber 209, whereby the deposits adhering to the inner wall of the exhaust buffer chamber 209 can be uniformly removed over the entire circumference. That is, over-etching in the vicinity of the connection location of the cleaning gas supply pipe 249a can be suppressed, and generation of etching residue at a location away from the connection location of the cleaning gas supply pipe 249a can be prevented.

  In the exhaust buffer chamber cleaning step (S112), the valve 245d is opened while the valves 243d, 244d, 246d, 247d, and 248d are closed in accordance with the supply of the cleaning gas from the cleaning gas supply pipe 249a. To do. In this way, the processing space 201 has a third gas supply pipe from the purge gas supply source 245b of the purge gas supply system 245 in accordance with the supply of the cleaning gas from the cleaning gas supply pipe 249a into the exhaust buffer chamber 209. The inert gas is supplied through the 245a and the common gas supply pipe 242. Here, “in accordance with the supply of the cleaning gas” means, in other words, “to prevent the cleaning gas from entering the exhaust buffer chamber 209 from entering the processing space 201”. Therefore, specifically, the supply timing of the cleaning gas and the inert gas starts with the supply of the inert gas in advance of the supply of the cleaning gas and then starts the supply of the cleaning gas thereafter, or at the latest. The supply of the inert gas is started simultaneously with the start of the supply of the cleaning gas.

  At this time, the MFC 245 c of the purge gas supply system 245 supplies the inert gas supplied into the processing space 201 so that the cleaning gas supplied into the exhaust buffer chamber 209 does not enter the processing space 201 from the communication hole 209 b. Adjust. Specifically, the supply amount of the inert gas is made larger than the supply amount of the cleaning gas.

  In this way, the cleaning gas supplied into the exhaust buffer chamber 209 is used only for the first cleaning process in the exhaust buffer chamber 209, and the deposit on the inner wall of the exhaust buffer chamber 209 is reliably removed. It becomes effective in doing. In addition, in the exhaust buffer chamber cleaning step (S112), it becomes possible to prevent the cleaning gas supplied into the exhaust buffer chamber 209 from entering the processing space 201, thereby the processing space cleaning step (S116) described later. It is possible to prevent over-etching or the like in the vicinity of the exhaust buffer chamber 209 in the processing space 201 when the process is performed.

  The exhaust buffer chamber cleaning step (S112) ends after the first cleaning process as described above is performed for a predetermined time. The predetermined time is not particularly limited as long as it is appropriately set in advance. Specifically, the exhaust buffer chamber cleaning process (S112) is completed by closing the valve 249d of the exhaust buffer chamber cleaning gas supply system 249 and the valve 245d of the purge gas supply system 245.

(Processing number determination step: S114)
After the exhaust buffer chamber cleaning step (S112) as described above, it is then determined whether or not the number of executions of the exhaust buffer chamber cleaning step (S112) has reached a predetermined number (S114).

  As a result, if the number of executions of the exhaust buffer chamber cleaning step (S112) has not reached the predetermined number, the number of executions is added by one and then a new wafer 200 waiting next is added. Then, a state in which a series of steps (S102 to S112) starting from the substrate carry-in / placement step (S102) can be performed is made. On the other hand, if the number of executions of the exhaust buffer chamber cleaning process (S112) reaches a predetermined number, the process proceeds to the processing space cleaning process (S116).

(Processing space cleaning step: S116)
In the processing space cleaning step (S116), the valve 248d is opened while the valves 243d, 244d, 245d, 246d, 247d, and 249d are closed. Thus, the cleaning gas is supplied to the processing space 201 from the processing space cleaning gas supply source 248b of the processing space cleaning gas supply system through the third gas supply pipe 245a and the common gas supply pipe 242. become. The supplied cleaning gas removes deposits (such as reaction byproducts) in the processing space 201. The cleaning process performed by supplying the cleaning gas into the processing space 201 from the processing space cleaning gas supply system is hereinafter referred to as “second cleaning process”.

  Incidentally, the deposit in the processing space 201 is a film that is less likely to be peeled off than that in the exhaust buffer chamber 209. This is because the deposit on the inner wall of the exhaust buffer chamber 209 is deposited under conditions different in temperature and pressure from the film formation conditions, so that the film thickness, film density, etc. are not stable. This is because the kimono is a film having a stable film thickness, film density, and the like because it adheres under the same conditions of temperature and pressure as the film formation conditions. Therefore, the cleaning gas used in the second cleaning process performed in the processing space cleaning process (S116) requires a higher cleaning power than the cleaning gas used in the first cleaning process performed in the exhaust buffer chamber cleaning process (S112). It becomes.

  Therefore, in the second cleaning process performed in the process space cleaning process (S116), a cleaning gas having higher activity is supplied than in the first cleaning process performed in the exhaust buffer chamber cleaning process (S112). The activity here means the energy of the cleaning gas. If the activity is high and the energy is high, the cleaning power is high, and even a dense film can be removed by the cleaning process.

  If the processing space cleaning gas supply source 248b and the exhaust buffer chamber cleaning gas supply source 249b are provided separately, the supply of the high energy cleaning gas is realized by supplying different types of cleaning gas from each. . That is, high-energy cleaning gas with high activity is supplied from the processing space cleaning gas supply source 248b, and low-energy cleaning gas with low activity is supplied from the exhaust buffer chamber cleaning gas supply source 249b.

  However, the supply of the high energy cleaning gas is performed as described below even when the processing space cleaning gas supply source 248b and the exhaust buffer chamber cleaning gas supply source 249b supply the same kind of cleaning gas. Realization is possible.

  Specifically, for example, in the second cleaning process performed in the process space cleaning step (S116), the heater 213 is turned on. By doing so, the energy of the cleaning gas supplied during the second cleaning process is made higher than the energy of the cleaning gas supplied during the first cleaning process performed in the exhaust buffer chamber cleaning step (S112). Is possible. By supplying such a high energy cleaning gas, a dense film can be removed by the cleaning process in the second cleaning process as compared with the first cleaning process.

  Further, for example, in order to supplement the energy of the cleaning gas supplied in the second cleaning process, the heater 213 is not limited to being turned on. The energy may be higher than the cleaning gas supplied at the time. That is, when the cleaning gas fills the shower head 230 and the processing space 201 during the second cleaning process, power is applied by the high frequency power supply 252 and impedance is matched by the matching unit 251 to clean the shower head 230 and the processing space 201. A gas plasma may be generated. Further, if the cleaning gas supplied during the first cleaning process is in a plasma state, the matching unit 251 and the high-frequency power source are configured so as to generate plasma with higher energy than that during the second cleaning process. 252 is controlled.

(Implementation frequency of the first cleaning process and the second cleaning process)
As described above, in the substrate processing apparatus 100, after the first cleaning process is performed a predetermined number of times in the exhaust buffer chamber cleaning process (S112), the second cleaning process is performed in the process space cleaning process (S116). That is, the controller 260 that controls these steps (S112, S116) performs the first cleaning process for supplying the cleaning gas from the cleaning gas supply pipe 249a into the exhaust buffer chamber 209 and the processing space cleaning gas into the processing space 201. The execution frequency of the second cleaning process for supplying the cleaning gas from the supply system is made different, and the execution frequency of the first cleaning process is made higher than the execution frequency of the second cleaning process. This is for the reason described below.

  The deposits on the inner wall of the exhaust buffer chamber 209 are deposited under conditions different in temperature and pressure from the film formation conditions, so the film thickness, film density, etc. are not stable, and thermal stress or physical stress It is easy to peel off when applied. On the other hand, the deposit in the processing space 201 is a film having a stable film thickness, film density, and the like because it adheres under the same conditions of temperature and pressure as the deposition conditions. That is, the deposit on the inner wall of the exhaust buffer chamber 209 is more fragile and easier to peel than the deposit on the processing space 201. For this reason, it is conceivable that deposits on the inner wall of the exhaust buffer chamber 209 may be peeled off due to pressure fluctuations for switching the gas supply. Thus, the controller 260 controls the frequency of performing the first cleaning process to be higher than the frequency of performing the second cleaning process.

(5) Effects According to the Embodiment According to the present embodiment, one or more effects described below are exhibited.

(A) According to this embodiment, with respect to the exhaust buffer chamber 209 having a space provided so as to surround the outer periphery of the processing space 201, a cleaning gas supply pipe communicating with the space of the exhaust buffer chamber 209 is provided. The cleaning gas is supplied directly using 249a. Therefore, even when unnecessary films or by-products are deposited as deposits on the inner wall of the exhaust buffer chamber 209, it can reach the exhaust buffer chamber 209 before deactivating the cleaning gas. Deposits can be reliably removed, and as a result, the exhaust buffer chamber 209 can be sufficiently cleaned. In addition, since the cleaning process for the exhaust buffer chamber 209 is performed in the exhaust buffer chamber cleaning step (S112), the operating efficiency of the apparatus is reduced unlike the case where the worker manually performs the apparatus maintenance. It can be said that the cleaning process can be performed satisfactorily.

  Moreover, according to the present embodiment, the cleaning gas supply pipe 249a is connected to the connecting hole 209b and the gas flow blocking wall 209a (that is, slightly upstream in the gas flow direction from the gas flow blocking wall 209a). ), The cleaning gas is supplied into the exhaust buffer chamber 209. Therefore, the cleaning process for removing the deposit is effectively performed on the gas flow blocking wall 209a in which the deposit easily adheres in the exhaust buffer chamber 209. It becomes possible.

  That is, according to the present embodiment, even when the gas is exhausted from the processing space 201 using the exhaust buffer chamber 209, the cleaning process for the exhaust buffer chamber 209 can be performed sufficiently and satisfactorily. it can.

(B) According to the present embodiment, the cleaning gas supply pipes 249a are connected to the exhaust buffer chamber 209 at a plurality of locations or via the gas supply grooves 249e that are continuous in the circumferential direction surrounding the processing space 201. Therefore, the supply of the cleaning gas to the exhaust buffer chamber 209 can be made uniform, and the cleaning gas is intensively supplied to a specific location (for example, in the vicinity of the connection location of the cleaning gas supply pipe 249a). Can be suppressed. Therefore, deposits in the exhaust buffer chamber 209 can be uniformly removed over the entire circumference.

(C) Further, according to the present embodiment, the third gas supply pipe 245a from the purge gas supply source 245b of the purge gas supply system 245 is synchronized with the supply of the cleaning gas from the cleaning gas supply pipe 249a into the exhaust buffer chamber 209. In addition, since the inert gas is supplied into the processing space 201 through the common gas supply pipe 242, the cleaning gas supplied into the exhaust buffer chamber 209 enters the processing space 201 in the exhaust buffer chamber cleaning step (S112). Can be prevented. Therefore, even when the cleaning gas is supplied into the exhaust buffer chamber 209, overetching or the like in the vicinity of the exhaust buffer chamber 209 in the processing space 201 when the processing space cleaning step (S116) or the like is performed. Can be prevented.

(D) Further, according to the present embodiment, the first cleaning process performed in the exhaust buffer chamber cleaning step (S112) and the second cleaning process performed in the processing space cleaning step (S116) are made different in frequency. The execution frequency of the first cleaning process is set higher than the execution frequency of the second cleaning process. Therefore, even if the deposits on the inner wall of the exhaust buffer chamber 209 are more brittle than the deposits in the processing space 201 and are easily peeled off, by increasing the cleaning frequency for the exhaust buffer chamber 209, It is possible to appropriately remove deposits on the surface. That is, even if the deposits on the inner wall of the exhaust buffer chamber 209 may be easily peeled off due to pressure fluctuation when switching the gas supply, the deposits enter the processing space 201 and are on the wafer 200. It is possible to prevent the film characteristics from being adversely affected and the yield from being lowered.

(E) According to the present embodiment, the activity of the cleaning gas supplied in the first cleaning process is lower than the activity of the cleaning gas supplied in the second cleaning process. That is, since the deposits on the inner wall of the exhaust buffer chamber 209 are more brittle than the deposits in the processing space 201 and easily peeled off, the energy of the cleaning gas supplied into the exhaust buffer chamber 209 in the first cleaning process is reduced to the second level. It is set lower than the energy of the cleaning gas supplied into the processing space 201 in the cleaning process. By doing so, overetching in the exhaust buffer chamber 20 can be prevented even when the cleaning gas is directly supplied into the exhaust buffer chamber 209.

(F) According to the present embodiment, the energy of the cleaning gas supplied during the second cleaning process is set by turning on the heater 213 during the second cleaning process performed in the processing space cleaning step (S116). Even when a dense film is adhered in the processing space 201, the film can be reliably removed.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

  For example, in the above-described embodiment, the film forming process is exemplified as the process performed by the substrate processing apparatus 100, but the present invention is not limited to this. That is, in addition to the film formation process, a process for forming an oxide film or a nitride film, or a process for forming a film containing metal may be used. Further, the specific content of the substrate processing is not questioned and can be suitably applied not only to the film forming processing but also to other substrate processing such as annealing processing, oxidation processing, nitriding processing, diffusion processing, and lithography processing. Furthermore, the present invention provides other substrate processing apparatuses such as annealing processing apparatuses, oxidation processing apparatuses, nitriding processing apparatuses, exposure apparatuses, coating apparatuses, drying apparatuses, heating apparatuses, and processing apparatuses using plasma. It can be suitably applied to. In the present invention, these devices may be mixed. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Moreover, it is also possible to add, delete, or replace another configuration for a part of the configuration of each embodiment.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

[Appendix 1]
According to one aspect of the invention,
A processing space for processing a substrate placed on the substrate placement surface;
A gas supply system for supplying gas into the processing space from the side facing the substrate mounting surface;
An exhaust buffer chamber configured to include at least a communication hole communicating with the processing space at a side of the processing space, and a gas flow blocking wall extending in a direction to block a gas flow through the communication hole;
A gas exhaust system for exhausting the gas flowing into the exhaust buffer chamber;
A cleaning gas supply pipe for supplying a cleaning gas into the exhaust buffer chamber from a connection point provided between the communication hole and the gas flow blocking wall;
A substrate processing apparatus is provided.

[Appendix 2]
Preferably,
The exhaust buffer chamber has a space having the gas flow blocking wall as one side wall, and the communication hole is formed in another side wall facing the one side wall, and the space is located on a side of the processing space. The substrate processing apparatus according to attachment 1, wherein the substrate processing apparatus is configured to extend so as to surround an outer periphery.

[Appendix 3]
According to another aspect of the invention,
A processing space for processing a substrate placed on the substrate placement surface;
A gas supply system for supplying gas into the processing space from the side facing the substrate mounting surface;
An exhaust buffer chamber having a space provided so as to surround a lateral outer periphery of the processing space, and configured so that a gas supplied into the processing space flows into the space;
A gas exhaust system for exhausting the gas flowing into the exhaust buffer chamber;
A cleaning gas supply pipe which communicates with the space constituting the exhaust buffer chamber and supplies a cleaning gas into the exhaust buffer chamber;
A substrate processing apparatus is provided.

[Appendix 4]
Preferably,
The cleaning gas supply pipe communicates with the space between a communication hole serving as a gas flow path from the processing space to the exhaust buffer chamber and a side wall on an outer peripheral side in the space constituting the exhaust buffer chamber. The substrate processing apparatus according to attachment 3 is provided in which a connection portion is provided.

[Appendix 5]
Preferably,
The substrate processing according to any one of appendices 1 to 4, wherein the cleaning gas supply pipe is connected to the exhaust buffer chamber at a plurality of locations or via a gas supply groove continuous in a circumferential direction surrounding the processing space. An apparatus is provided.

[Appendix 6]
Preferably,
The gas supply system includes an inert gas supply system that supplies an inert gas into the processing space;
The inert gas supply system supplies the inert gas into the processing space prior to the start of supply of the cleaning gas from the cleaning gas supply pipe into the exhaust buffer chamber or at the same time as the supply of the cleaning gas at the latest. The substrate processing apparatus according to any one of appendices 1 to 5 is provided.

[Appendix 7]
Preferably,
The gas supply system includes a processing space cleaning gas supply system for supplying a cleaning gas into the processing space;
Controlling the execution of a first cleaning process for supplying a cleaning gas from the cleaning gas supply pipe into the exhaust buffer chamber and a second cleaning process for supplying a cleaning gas from the processing space cleaning gas supply system into the processing space. A substrate processing apparatus according to any one of appendices 1 to 6 including a controller is provided.

[Appendix 8]
Preferably,
The substrate processing apparatus according to appendix 7, wherein the controller controls the execution frequency of the first cleaning process to be higher than the execution frequency of the second cleaning process.

[Appendix 9]
Preferably,
The substrate processing apparatus according to appendix 7 or 8, wherein the activity of the cleaning gas supplied in the first cleaning process is lower than the activity of the cleaning gas supplied in the second cleaning process.

[Appendix 10]
Preferably,
A heater as a heating source is embedded in the substrate mounting surface,
The heater is controlled to be turned on / off by the controller,
The substrate controller according to any one of appendices 7 to 9, wherein the controller controls to turn on the heater during the second cleaning process.

[Appendix 11]
According to another aspect of the invention,
A space provided to surround a lateral outer periphery of the processing space while supplying gas from the side facing the substrate mounting surface to the substrate mounted on the substrate mounting surface in the processing space A substrate processing step of processing the substrate in the processing space by exhausting gas from the processing space using an exhaust buffer chamber having:
An exhaust buffer chamber cleaning step of cleaning the exhaust buffer chamber by supplying a cleaning gas into the exhaust buffer chamber from a cleaning gas supply pipe communicating with the space constituting the exhaust buffer chamber;
A method for manufacturing a semiconductor device is provided.

[Appendix 12]
In the exhaust buffer chamber cleaning step, prior to the start of supply of the cleaning gas from the cleaning gas supply pipe into the exhaust buffer chamber, or at the same time as the supply of the cleaning gas at the latest, the substrate placement surface in the processing space The method for manufacturing a semiconductor device according to attachment 11 is provided in which the supply of the inert gas is started from the side opposite to.

[Appendix 13]
Preferably,
A processing space cleaning step of cleaning the inside of the processing space by supplying a cleaning gas from the side facing the substrate mounting surface in a state where there is no substrate on the substrate mounting surface with respect to the processing space. ,
The semiconductor device manufacturing method according to appendix 11 or 12, wherein the exhaust buffer chamber cleaning step is performed more frequently than the processing space cleaning step.

[Appendix 14]
According to another aspect of the invention,
A space provided to surround a lateral outer periphery of the processing space while supplying gas from the side facing the substrate mounting surface to the substrate mounted on the substrate mounting surface in the processing space A substrate processing step of processing the substrate in the processing space by exhausting gas from the processing space using an exhaust buffer chamber having:
An exhaust buffer chamber cleaning step of cleaning the exhaust buffer chamber by supplying a cleaning gas into the exhaust buffer chamber from a cleaning gas supply pipe communicating with the space constituting the exhaust buffer chamber;
A program for causing a computer to execute is provided.

DESCRIPTION OF SYMBOLS 100 ... Substrate processing apparatus 200 ... Wafer (substrate)
201 ... Processing space 209 ... Exhaust buffer chamber 209a ... Gas flow blocking wall 209b ... Communication hole 211 ... Substrate mounting surface 222 ... Second exhaust pipe 230 ... Shower head 242 ... Common gas supply pipe 249a ... Cleaning gas supply pipe

Claims (9)

A processing space for processing a substrate placed on the substrate placement surface;
A processing space gas supply system for supplying a processing gas or an inert gas into the processing space from the side facing the substrate mounting surface;
An exhaust buffer chamber configured to include at least a communication hole communicating with the processing space at a side of the processing space, and a gas flow blocking wall extending in a direction to block a gas flow through the communication hole;
A gas exhaust system for exhausting the gas flowing into the exhaust buffer chamber;
An exhaust buffer chamber cleaning gas supply system having a cleaning gas supply pipe for supplying a cleaning gas into the exhaust buffer chamber from a connection point provided between the communication hole and the gas flow blocking wall;
Without supplying the cleaning gas from the exhaust buffer chamber cleaning gas supply system to the exhaust buffer chamber in a state where the substrate is placed on the substrate mounting surface, the processing gas or the processing gas from the processing space gas supply system An inert gas is supplied, the substrate is processed while a film is deposited on the gas flow blocking wall, and the exhaust gas is discharged from the exhaust buffer chamber cleaning gas supply system in a state where the substrate does not exist on the substrate mounting surface. While supplying the cleaning gas to the buffer chamber and removing the film deposited on the gas flow blocking wall, the cleaning gas enters the processing space without supplying the processing gas from the processing space gas supply system. The processing space gas supply system and the exhaust buffer chamber cleaning so as not to supply the inert gas from the processing space gas supply system to the processing space. A substrate processing apparatus comprising a controller for controlling the gas supply system. The controller includes the processing space gas supply system and the processing space gas supply system so that the supply amount of the inert gas is larger than the supply amount of the cleaning gas while the cleaning gas is supplied to the exhaust buffer chamber from the cleaning gas supply pipe. The substrate processing apparatus according to claim 1, wherein an exhaust buffer chamber cleaning gas supply system is controlled. The exhaust buffer chamber has an exhaust buffer space provided so as to surround a lateral outer periphery of the processing space, and is configured such that a gas supplied into the processing space flows into the exhaust buffer space . The substrate processing apparatus according to claim 1 or 2. The said cleaning gas supply pipe | tube is connected with respect to the said exhaust buffer chamber through the gas supply groove | channel which continues in the circumferential direction surrounding the said process space in multiple places. Substrate processing equipment. The processing space gas supply system supplies inert gas into the processing space prior to the start of supply of the cleaning gas from the cleaning gas supply pipe into the exhaust buffer chamber or at the same time as the supply of the cleaning gas at the latest. The substrate processing apparatus according to claim 1, wherein supply is started. The processing space gas supply system includes a processing space cleaning gas supply system for supplying a cleaning gas into the processing space,
The controller includes a first cleaning process for supplying a cleaning gas from the cleaning gas supply pipe into the exhaust buffer chamber, and a second cleaning process for supplying a cleaning gas from the processing space cleaning gas supply system into the processing space. The substrate processing apparatus according to any one of claims 1 to 5, wherein the substrate processing apparatus controls the execution and controls the execution frequency of the first cleaning process to be higher than the execution frequency of the second cleaning process. The substrate processing apparatus according to claim 6, wherein the activity of the cleaning gas supplied in the first cleaning process is lower than the activity of the cleaning gas supplied in the second cleaning process. A substrate placed on a substrate placement surface in the processing space is surrounded by a lateral outer periphery of the processing space while supplying a processing gas or an inert gas from the side facing the substrate placement surface. The processing space or the inert gas is exhausted from the processing space using an exhaust buffer chamber having a space provided in the processing space, and a film is deposited on the gas flow blocking wall constituting the exhaust buffer chamber. A substrate processing step for processing the substrate in the substrate;
A cleaning gas is supplied into the exhaust buffer chamber from a cleaning gas supply pipe communicating with the space constituting the exhaust buffer chamber in a state where no substrate exists on the substrate placement surface, and is deposited on the gas flow blocking wall. Cleaning the exhaust buffer chamber so as to remove the formed film, and removing the film deposited on the gas flow blocking wall from the side facing the substrate mounting surface into the processing space. without supplying, so that the cleaning gas into the processing space does not enter the exhaust buffer chamber cleaning step of supplying the inert gas into the processing space from the side facing the substrate mounting surface,
A method for manufacturing a semiconductor device comprising: A substrate placed on a substrate placement surface in the processing space is surrounded by a lateral outer periphery of the processing space while supplying a processing gas or an inert gas from the side facing the substrate placement surface. The processing space or the inert gas is exhausted from the processing space using an exhaust buffer chamber having a space provided in the processing space, and a film is deposited on the gas flow blocking wall constituting the exhaust buffer chamber. A procedure for processing said substrate in;
A cleaning gas is supplied into the exhaust buffer chamber from a cleaning gas supply pipe communicating with the space constituting the exhaust buffer chamber in a state where no substrate exists on the substrate placement surface, and is deposited on the gas flow blocking wall. Cleaning the exhaust buffer chamber so as to remove the formed film, and removing the film deposited on the gas flow blocking wall from the side facing the substrate mounting surface into the processing space. the without supplying, so that the cleaning gas into the processing space to prevent entry of the procedure for supplying the inert gas into the processing space from the side facing the substrate mounting surface in the computer depending on the substrate processing apparatus The program to be executed.